Treatment of textiles with polyepoxides and polyamides



nite tates atent l 3,019,076 I TREATMENT OF TEXTILES WETH POLY- EPOXIDES AND POLYAMIDES Clay E. Pardo, .lr., Albany, and Richard A. UConnell, El Cerrito, Calif., assignors to the United States of America as represented by the decretary of Agriculture No Drawing. Filed .luly 22, 1958, Ser. No. "750,274

11 Claims. (Cl. 8-128) (Granted under Title 35, US. Code (1952), see. 266) A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This application is a continuation-in-part of our copending application, Ser. No. 619,3 64, filed Oct. 30, 1956, now abandoned.

This invention relates to and has among its objects the treatment of textiles in order to improve their dimensional stability. A particular object of the invention concerns the treatment of woolen textiles to produce modified textiles which exhibit a marked resistance to shrinking and felting as compared with the original wool. The invention also encompasses the improved woolen textiles as novel products. Further objects and advantages of the invention will be evident from the following description.

It is well known in the art that many' textile fibers exhibit poor dimensional stability. For example, woolen textiles are subject to severe shrinking and felting when laundered in aqueous media. Various methods of stabilizing textiles by applying resinous material have been advocated but these known methods have not been found to be satisfactory in that the textile is made stiff and harsh, or, if the amount of resinous material is limited to avoid this stiffening effect, little improvement in dimensional stability is attained.

In accordance with the invention, woolen textile materials are impregnated with a polyepoxide and a polyamide and then cured by application of heat to produce a resinous polyepoxide-polyamide reaction product on the fibers of the textile. This procedure yields modified textiles which are dimensionally stabilized yet which retain unimpaired their intrinsic properties which make them useful for textile purposes. Thus, Wool treated in accordance with the invention can be washed in aqueous media since it is highly resistant to shrinking and felting. However the treated wool is still useful for usual textile applications since the hand, resiliency, porosity, tensile strength, and other valuable properties of the textile me retained. A particular advantage of the treatment in accordance with the invention is that the improvement is essentially permanent; the treated textiles can be laundered repeatedly without losing their dimensional stability. A further advantage of the invention is that a relatively minor proportion of active agents deposited on the textile impart a very drastic improvement in dimensional stability. For example, wool treated in accordance with the invention with less than 10% of active material (polyepoxide and polyamide) displays virtually no shrinkage on repeated washing in aqueous media. The attainment of such a disproportionate improvement of the properties of the textile is indeed a result not to be expected by prior knowledge in this field. A further advantage of the process of the invention is that textiles treated in accordance with the invention can be dyed by ordinary dyeing procedures. For example Wool treated by the procedures herein set forth may be dyed in conventional manner with the usual types of acid, chrome, premetalized, and milling dyes.

The process in accordance with the invention is to be distinguished from procedures wherein resinous materials are applied on textiles as continuous films. In such procedures the hand of the textile is completely altered so that the treated textile has more of the qualities of a plastic film than of a textile. Such products are totally unsuitable for conventional textile applications. In the process of the invention the polyepoxide and polyamide are applied in relatively small amounts and by the curing process react in situ on the textile fibers forming a resin coating on individual fibers rather than a continuous coating on the textile itself. Accordingly, the products of the invention retain their essential textile properties and are eminently useful for all conventional textile applications, e.g., for the fabrication of suits, dresses, shirts, and other garments.

It is to be noted that by the use of a combination of polyepoxide and polyamide, results are obtained that cannot be achieved with either of these agents alone. Thus if wool is treated solely with either the polyepoxide or the polyamide and then heat cured, an inferior degree of shrinkproofing is afforded. For example, woolen cloths were treated with equal amounts of (a) polyepoxide alone, (b) polyamide alone, and (c) a mixture of the two agents. The cloths were cured and subjected to laundering and measurement of shrinkage. It was observed that area shrinkage of samples a and b were seven times as great as the area shrinkage: of sample 0.

Basically, the process of the invention involves applying to the textile limited amounts of polyepoxide and polyamide and then curing the treated textile by subjecting it to heat. Prior to applying the polyepoxide and polyamide, the textile may be subjected to certain pretreatments as further described below.

As noted briefly above, an essential step in the process of the invention is to impregnate the textile with the poly epoxide and polyamide. To achieve uniform deposition of these agents on the textile, it is preferred that they be applied to the textile in the form of a dispersion in a volatile, inert, liquid carrier. The expression dispersion is used herein in a generic sense as including true solutions, colloidal solutions, suspensions, emulsions, and the like. The two agents, polyepoxide and polyamide, may both be in a single dispersion or separate dispersions of each may be applied serially to the textile. The dispersion or dispersions may be applied to the textile in any of the usual ways as by immersion, brushing, spraying, etc. To assist in wetting the textile and removing excess liquid, it may be run through padding rolls, wringer rolls, or the like. The proportion of active material in the dispersion or dispersions and the amount of liquid left in the textile is usually selected so that there is deposited on the textile about 0.5 to 10% of its weight of the mixture of polyepoxide and polyamide. In general, the greater the proportion of these agents, the greater will be the dimensional stability of the treated textile.

In forming the dispersion for impregnating the textile, water may be used as the liquid carrier where the selected polyepoxide and polyamide are soluble in this medium. In many cases organic solvents are more preferably employed, for example, methanol, ethanol, propanol, isopropyl alcohol, any of the isomeric butyl alcohols, acetone, benzene, toluene, monomethyl ether of ethylene glycol, monoethyl ether of ethylene glycol, etc. Mixtures of solvents may be used and particularly advantageous are mixtures of (a) hydrocarbon solvent such as benzene, toluene, petroleum naphthas, xylene, etc. and (b) alcohol, hydroxy-ethenor ketone solvents, such as butanols, acetone, rnethyl-ethyl ketone, monomethyl ether of ethylene glycol, monoethyl ether of ethylene glycol, etc. The polyepoxide and polyamide may also be dissolved in solvent systems containing water and water-miscible solvents such as methanol, ethanol, propanol, isopropyl alcohol, acetone, etc. As noted above, both polyepoxide and polyamide may be dissolved in a single batch of solvent or separate solutions of the two agents may be prepared for serial application in any order to the textile. Wherethe solutions are applied serially, the textile may be dried after application of the first solution and prior to treatment with the second.

In accordance with a preferred embodiment of the invention, the polyepoxide and polyamide are deposited on the textile by impregnating it with an aqueous emulsion containing both the polyepoxide and polyamide. Such aqueous emulsions can be prepared by any of the known emulsification techniques. A preferred procedure is to dissolve the polyepoxide and polyamide in separate batches of alcohol and add these alcohol solutions to the water with vigorous agitation. in this manner the contact of the alcohol solutions with the water will precipitate the polyepoxide and polyamide in minute particles which are relatively easy to emulsify. To assist in forming and maintaining the emulsion, one may add a small proportion, on the order of 0.1 to of a conventional emulsifying agent. For such purpose one may employ agents such as soaps, long chain alkyl sodium sulphates or sulphonates, long chain alkyl benzene sodium sulphonates, esters of sulphosuccinic acid, etc., typical examples being sodium oleate, sodium lauryl sulphate, sodium dodecane, sulphonate, sodium alkyl (C -C benzene sulphonate, sodium dioctylsulphosuccinate, etc. Preferably, agents of the non-ionic type are used, for example, the reaction products of ethylene oxide with fatty acids, polyhydric alcohols, alkyl phenols, and so forth. Typical examples of such agents are a polyoxyethylene stearate containing 20 oxyethylene groups per mol, a polyoxyethylene ether of sorbitan monolaurate containing 16 oxyethylene groups per mol, a distearate of polyoxyethylene ether of sorbitol containing oxyethylene groups per mol, iso-octyl ether of polyethylene glycol, and so forth. Cationic agents may also be used for example, long-chain alkyl trimethyl ammonium chlorides, bromides, and methosulphates. Other suspending agents such as gums, gelatin, pectin, soluble starch, dextrins, etc. can of course be employed to keep the active agents in suspension. Although water is ordinarily the primary vehicle in the emulsions, the emulsions may contain, in addition to water, organic water-miscible solvents such as methanol, ethanol, propanol, isopropyl alcohol, acetone, and the like.

The total concentration of polyepoxide and polyamide in the emulsion or other type of dispersion is not critical and may be varied depending on the amount of these agents to be deposited on the textile, on the type of impregnation technique employed, and particularly on the wet pickup of dispersion by the textile. For practical purposes dispersions containing about from 1% to 20%, usually about from 5 to 10%, of polyepoxide and polyamide are generally used.

As noted hereinabove, it is not essential to employ a single emulsion containing both polyepoxide and polyamide. These agents may be separately prepared as aqueous emulsions and these emulsions applied serially in any order to the textile. If desired, the textile may be dried after application of the first emulsion and prior to application of the second emulsion.

After the textile has been impregnated with the polyepoxide and polyamide, it is subjected to a heat curing treatment. Generally the impregnated textile is dried by conventional techniques prior to curing. This curing operation involves subjecting the impregnated textile to an elevated temperature to promote reaction between the polyepoxide and the polyamide whereby there is formed an insoluble resinous reaction product on the fibers of the textile. This resinous material permanently stabilizes the textile since it is essentially insoluble in water, aqueous laundering media, dry cleaning solvents,

etc. The mechanism of the interaction between the polyepoxide and the polyamide is believed to primarily involve reaction of (a) the free primary amine groups (-NH and free secondary amine groups (NH) of the polyamide with (b) the epoxy groups of the polyepoxide to form direct NC- bonds between the polyamide and polyepoxide. Also, reaction may take place between free carboxyl groups in the polyamide and the epoxy groups of the polyepoxide forming ester linkages between the two compounds. In addition, reaction take place between the epoxy groups of the polyepoxide and amino residues in the wool.

The curing treatment is generally conducted at temperatures in the range 50 to 200 C., more preferably to 200 C. The time of cure will vary depending on such factors as the reactivity of the polyepoxide and polyamide selected and particularly on the temperature at which the cure is carried out. For example, the cure may require more than 30 minutes at 180 C., about 10 to 36 minutes at C. about 3 to 15 minutes at C., and 5 minutes or less at C. A preferred type of treatment involves first drying the treated textile in a current of air at about 20 to 50 C. to remove liquid carrier (water, alcohol, or other solvent) and then curing in an oven at about 125-150 C. for about 20 to 10 minutes.

The curing may be ett'ectuated through the medium of a hot gas or liquid. It has been observed that a more rapid cure is attained when the treated textile is contacted with steam or boiling water as compared to heating in an oven where heating is accomplished through contact with hot air at the same temperature. Where the cure is accomplished by boiling the treated textile in water, it is preferred that the water he maintained at a pH of about 7 to 8 since it has been observed that at lower pHs the degree of shrinkproofing is lessened whereas at higher pHs the fiber may tend to develop a yellow coloration. To maintain the pH of the water at the proper pH during the cure, one may add any conventional buifering agent such as sodium bisulphate, citric acid, boric acid, disodium hydrogen phosphate, borax, sodium carbonate, etc. Whether an alkaline or an acid buffer is required will of course depend on such considerations as the chemical nature of the agents deposited on the fiber, the impurities associated wit-h these agents, the type of water used, and so forth.

After the textile material is cured, it may be washed in water or preferably conventional aqueous laundering media to remove excess resinous reaction product which does not contribute to dimensional stabilization but which causes a temporary stiffening of the textile. During the agitation with the aqueous medium this excess material, probably existing in interstices in the textile, is removed by mechanical action and the flexibility and softness of the textile is restored. The textile material is then dried in the usual way and is ready for use.

To ensure uniform deposition of the polyepoxide and polyamide on the textile, it is preferred that the textile prior to application of these agents be in a clean state and free from spinning oils, lubricants, and other extraneous materials. To this end the textile, before application of the polyepoxide and polyamide, may be scoured with conventional aqueous Washing media containing soap or synthetic detergents. In the alternative, the textile may be extracted with fat-solvents such as benzene, Stoddard solvent, naphtha, carbon tetrachloride, ethanol, or the like. It is also preferred that the textile material be in a neutral to slightly alkaline state (pH about 7 to 9) prior to application of the polyepoxide and polyamide since acid conditions (as may be encountered with wool dyed in acid baths) will hinder the desired reaction between epoxy groups of the polyepoxide and the amino groups of the polyamide. Generally, where the textile is washed in conventional soap or de tergent-containing media it will be at a proper pH for the treatment. If the textile is in an acid condition it may be properly conditioned by soaking in a dilute solution (about 0.1 to 5%) or" a mild alkaline agent such as sodium carbonate, sodium bicarbonate, borax, trisodium phosphate, tetrasodium pyrophosphate, sodium metaphosphate, ammonia, sodium acetate, soap, or the like. After such soaking the textile may be rinsed with water and dried. It has also been observed that the shrinkproofing effect is enhanced if the wool is pretreated with peroxide prior to application of the polyepoxide and polyamide. To this end the wool is soaked in an aqueous bath, adjusted to a pH of about 9 to by addition of any of the afore-mentioned mild alkaline agents, or their equivalent, and suflicient hydrogen peroxide to provide a concentration of about /2 to 4 volumes. The wool is soaked in the bath long enough to ensure thorough impregnation. If desired the bath may be heated for example to about 50 to 60 C. A preferred treatment is to soak the wool in an aqueous solution containing about 0.8% tetrasodium pyrophosphate and 2 volumes of hydrogen peroxide. The soak is continued for about one hour at 50 C. The Wool is then removed from the bath, rinsed, dried, and treated as described above.

The polyepoxides used in accordance with the invention are organic compounds having at least two epoxy groups per molecule and may be saturated or unsaturated, aliphatic, cycloaliphatic, aromatic or heterocyclic and may be substituted with non-interfering substituents such as hydroxyl groups, ether radicals, and the like. Polyepoxides containing ether groups, generally designated as polyepoxide polyethers, may be prepared as well known in the art by reacting a polyol with a halogen-containing epoxide employing at least 2 moles of the halogen-containing epoxide per mole of polyol. Thus, for example, epichlorhydrin may be reacted with a polyhydric phenol in an alkaline medium. In another technique the halogencontaining epoxide is reacted with a polyhydric alcohol in the presence of an acid-acting catalyst such as hydrofluoric acid or boron trifluoride and the product is then reacted with an alkaline compound to effect a dehydrohalogenation. A preferred example of the halogencontaining epoxide is epichlorhydrin; others are epibrornhydrin, epiodohydrin, 3chloro-1,2-epoxybutane, 3-bromo- 1,2-epoxyhexane, and 3-chloro-1,2-epoxyoctane. Examples of polyols which may be reacted with the halogen containing epoxide are glycerol, diglycerol, ropylene glycol, ethylene glycol, diethylene glycol, butylene glycol, hexanetriol, sorbitol, mannitol, pentanetriol, pentaerythritol, dipentaerythritol, polyglycerol, dulcitol, inositol,'carbohydrates, methyltrimethylol propane, 2,6-octa- 6 2,2-bis(2,3-epoxypropoxyphenyl)propane; glycerol triglycidyl ether; mannitol tetraglycidyl ether; pentaerythritol tetraglycidyl ether; sorbitol tetraglycid'yl ether; glycerol di-glycidyl ether; etc. It is evident that the polyepoxide polyethers may or may not contain hydroxy groups, depending primarily on the proportions of halogen-containing epoxide and polyol employed. Polyepox ide polyethers containing polyhydroxyl groups may also be prepared by reacting, in known manner, a polyhydric alcohol or polyhydric phenol with a polyepoxide in an alkaline medium. Illustrative examples are the reaction product of glycerol and diglycidyl ether, the reaction product of sorbitol and bis(2,3-epoxy-2-methylpropyl) ether, the reaction product of pentaerythritol and 1,2,3,5- diepoxy pentane, the reaction product of 2,2-bis(parahydroxyphenyl)propane and bis(2,3-epoxy-2-rnethylpropyl)ether, the reaction product of resorcinol and diglycidyl ether, the reaction product of catechol and diglycidyl ether, and the reaction product of 1,4-dihydroxycyclohexane and diglycidyl ether.

Polyepoxides which do not contain ether groups may be employed as for example 1,2,5,6-diepoxyhexane; butadiene dioxide (that is, 1,2,3,4-diepoxybuta;ne); isoprene dioxide; limonene dioxide.

For use in accordance with the invention, we prefer the polyepoxides which contain ether groups, that is, polyepoxide polyethers. More particularly we prefer to use the polyepoxide polyethers of the class of glycidyl polyethers of polyhydric alcohols or glycidyl polyethers of polyhydric phenols. These compounds may be considered as being derived from a polyhydric alcohol or polyhydric phenol by etherification with at least two glycidyl groups (un on-011F0- The alcohol or phenol moiety may be completely etherified or may contain residual hydroxy groups. Typical examples of compounds in this category are the glycidyl polyethers of glycerol, glycol, diethylene glycol, 2,2-bis- (parahydroxyphenol) propane, or any of the other polyols listed hereinabove as useful for reaction with halogencontaining epoxides. Many of the specific glycidyl polyethers derived from such polyols are set forth hereinabove. Particularly preferred among the glycidyl polyethers are those derived from 2,2-bis(parahydroxyphenyl)propane and those derived from glycerol. The compounds derived from the first-named of these polyols have the structure-- wherein n varies between zero and about 10*, corresponding to a molecular weight about from 350 to 8,000. Of this class of polyepoxides we prefer to employ those compounds wherein n has a low value, i.e., less than 5, most preferably where n is zero.

In commerce, the polyepoxide polyethers are conventionally termed as epoxy resins even though the compounds are not technically resins in the state in which they are sold and employed because they are of relatively low molecular weight and thus do not have resinous properties as such. It is only when the compounds are cured that true resins are formed. Thus it will be found that manufacturers catalogs conventionally list as epoxy resins such relatively low-molecular weight products as the diglycidyl ether of 2,2-bis(parahydroxyphenoDpropane, the diglycidyl ether of glycerol, and similar polyepoxide polyethers having molecular Weights substantially less than 1,000. In Examples I to IV set forth herein the polyepoxides used for treating wool are referred to as resins following usual trade nomenclature but it is not 6 to be implied that these substances are in a truly resinous condition when applied to the textile.

It is within the purview of the invention to employ mixtures of different polyepoxides. Indeed, it has been found that especially desirable results are attained by employing mixtures of two commercially-available polyepoxides, one being essentially a diglycidyl ether of glycerol, the other being essentially a diglycidyl ether of 2,2-bis(parahydroxyphenyl)propane. Thus it has been found that a mixture of these compounds produces a very desirable combination of maximum shrinkproofing effect coupled with a minimum alteration of the natural hand of the textile. Particularly preferred to attain such result are mixtures containing more than 1 and less than 10 parts by weight of the glycerol diglycidyl ether per part by weight of the diglycidyl ether of 2,2-bis(parahydroxyphenyl)propane.

The polyamides used in accordance with the invention are those derived from po'lyamines and polybasic acids. Methods of preparing these polyaniides by condensation of polyamines and polycarboxylic acids are well known in the art and need not be described here. One may prepare polyamides containing free amino groups or free carboxylic acid groups or both free amino and free carboxylic acid groups. enerally it is preferred to employ polyanrides which contain free amino groups since the active hydrogens on these groups are especially reactive with the epoxy groups of the polyepoxide to form insoluble polyepoxide-polyamide reaction products. The polyamides may be derived from such polyamines as ethylene diamine, diethylene triarnine, triethylene tetramine, tetraethylene pentarnine, 1,4-diamiuo butane, 1,3- diaminobutane, hexamethylene diamine, 3-(N-isopropylamine), 3,3-irnino-bispropylamine, and the like. Typical polycarboxylic acids which may be condensed with the polyamines to form polyamides are glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, isophthalic acid, terephthalic acid, betamethyl adpic acid, 1,2-cyclohexane dicarboxylic acid, malonic acid, polymerized fat acids, and the like. Depending on the amine and acid constituents and the conditions of condensation, the polyamides may have molecular weights varying about from 1,000 to 10,000 and melting points about from 200 C. Particularly preferred for the purpose of the invention are the polyanrides derived from aliphatic polyamines and polymeric fat acids. Such products are disclosed for example by Cowan et al., Patent No. 2,450,940. Typical of these polyamides are those made by condensing ethylene diamine or diethylene triamine with polymeric fat acids produced from the polymerization of drying or semi-drying oils, or the free acids, or simply aliphatic alcohol esters of such acids. The polymeric fat acids may typically be derived from such oils as soybean, linseed, tung, perilla, oiticica, cottonseed, corn, tall, sunflower, safliower, and the like. As well known in the art, in the polymerization the unsaturated fat acids combine to produce a mixture of dibasic and higher polymeric acids. Usually the mixture contains a preponderant proportion of dimeric acids with lesser amounts of trimeric and higher polymeric acids, and some residual monomeric acid. Particularly preferred are the polyamides of low melting point (about 2090 C.) which may be produced by heating together lower aliphatic polyamine, such as diethylene triamine, triethylene tetramine, 1,4-diaminobutane, 1,3-diaminobutane, and the like with the polymerized fat acids. Typical among these is a polyamide derived from diethylene triamine and dimerized soybean fatty acids. The polyamides derived from aliphatic polyamides and polymerized fat acids, like the polyepoxides, are often referred to in the trade as resins even though not technically resins in the state in which they are sold and applied. Reference to polyamide resin in Examples 1 to IV herein is not to be taken as an indication that the polyamide was a true resin when applied to the wool, rather the expression resin is used merely following commercial practice.

As noted above, the total amount of polyepoxide and polyamide deposited on the textile is about from 0.5 to 10% of the weight of the textile. The relative proportions of polyepoxide and polyamide may be varied widely, for example, from 0.1 to 10 parts by weight of polyamide per part by Weight of polyepoxide. In many cases mixtures containing 30 to 70% by weight of polyamide and 70 to 30% by Weight of polyepoxide give superior results. Since the number of reactive groups in the polyepoxide and polyamide may vary, the proportions for optimum results may be more accurately described by stoichiometric relations. Thus it is preferred that the polyamide be employed in such proportion as to provide about from 0.2 to 1.6 amino groups per epoxy group provided by the polyepoxide. The superior results achieved by using these proportions is illustrated in Example Vl wherein the ratios of reactive (i.e., primary or secondary) amino groups to epoxy groups were approximately: sample 3, 1.57 to 1; sample 4, 0.6 to 1; and sample 5, 0.2 to 1.

The process of the invention may be applied to allwool textiles or textiles containing wool blended with other fibers, for example: animal hair; mohair; silk; synthetic fibers made from proteins such as zein, casein, peanut protein, soybean protein, keratins, etc.; cellulosic fibers such as cotton, linen, rayon, viscose, cellulose, acetate, jute, hemp, etc.; nylon; Dynel; Orlon; Dacron; or other organic textile fibers. The expression woolcontaining textile as used herein is intended to encompass all-wool textiles and blended textiles containing a significant proportion, that is, at least 25% by weight of wool. The process of the invention may be applied to wool-containing textile materials in the form of fibers, threads, yarns, slivers, woven or knitted fabrics, or even garments made of woven or knitted fabrics. The textiles may be white or dyed goods.

The invention is further demonstrated by the following examples which are given only by way of illustration but not limitation.

EXAMPLE I An aqueous emulsion was prepared containing 1% of epoxy resin and 1% of polyamide. The epoxy resin was a commercial product being a reaction product of epichlorhydrin and glycerol. This material is a liquid at ordinary temperatures, has a viscosity of 0.9 to 1.5 poises at 25 C., and has an expoxide equivalent of 140-165. The polyamide was a commercial product being a condensation product of ethylene diamine and heat-polymerized high molecular weight fatty acids. The polyamide was a viscous liquid at ordinary temperatures with a viscosity of A A on the Gardner-Holdt scale at 25 C., and a specific gravity of 0.99 at 25 C.

The above emulsion was padded onto swatches of woolen cloth under conditions that the cloth took up about of its weight of the emulsion. The impregnated swatches were dried and partially cured by heating them in an oven for 1 hour at 50 C.

The dried cloth samples were then subjected to different curing treatments. Sample 1 was cured in an oven for 60 min. at C. Samples 2 to 6 were boiled 1 hour in water at dilferent pHs, as follows: Sample 2 at pH 3 obtained by adding to the water 1% Glaubers salt and 1% sodium bisulphate; samples 3 and 4 at pH 5 and 7, respectively, obtained by adding to the water appropriate amounts of Macllvaines buffer (a mixture of 0.1 N citric acid and 0.2 N di-sodium hydrogen phosphate); sample 5 at pH 8 obtained with. distilled Water; and sample 6 at pH 9 obtained by addition of borate buffer (sodium tetraborate and boric acid).

The cured samples of cloth and a sample of untreated cloth (control) were subjected to tests to measure their shrinkage characteristics. In these tests the cloth samples were subjected to a laundering operation wherein the cloth was violently agitated for 3 min. in a 0.5% solution of sodium oleate at 40 C. with a cloth to solution ratio of 1 to 35, the area of the cloth being measured before and after laundering. The washing tests were carried out in duplicate. The results are tabulated below, the shrinkage values being averages of the duplicate tests.

Table I SHRINKAGE OF WOOLEN CLOTH TREATED WITH 1% EPOXY RESIN AND 1% POLYAMIDE RESIN Area Shrinkage Sample Curing treatment after laundering,

percent in water at pH 8.-- in water at pH 9 6 Control.

EXAMPLE II The process of Example I was repeated with the only exception that the emulsion applied to the cloth contained 1.5% each of the epoxy resin and the polyamide. The results obtained are set forth below.

Table II SHRINKAGE OF WOOLEN CLOTH TREATED WITH 1.5% EPOXY RESIN AND 1.5% POLYAMIDE RESIN Area shrinkage Sample Curing treatment after laundering,

percent Oven cured. 1 hr. at 110 C 13.6 Boiled 1 hr in water at pH 3.. 28. 4 Bo1lcd 1 hr in water at, pH 5.- 28. 4 Boiled 1 hr in water at pH 7 4. Boiled 1 hr in water at pH 8 1. 8 Boiled '1 hr. in water at pH 9.- 2. 5 None 38. 9

1 EXAMPLE III emulsion. The impregnated cloths were dried in an oven at -50 C. for one hour. One batch of the dried cloths, representing samples treated at each of the concentration levels, were cured by subjecting them to dry heat in an oven at 110 C. for one hour. The other batch of dried cloths, also representing samples treated at each of the concentration levels, were cured by boiling in water for one hour. The results are set forth in the following tables:

This example illustrates the efilectiveness of the process of the invention to reduce the shrinkage of knitted goods.

Heavy 4-ply worsted light-tan wool yarn was knitted into tubular pieces about 22 inches long and 3 /2 inches in diameter. The knitted material was soaked overnight in a 1% solution of sodium acetate followed by a distilled water rinse to neutralize acidity remaining from previous dyeing of the yarn; One sample of the material was impregnated with an aqueous emulsioncontaining 5% epoxy resin, 5% polyamide resin, 0.5% of isooctyl ether of polyethylene glycol (Triton X-100), and 0.1% of polyoxyethylene sorbitan monopalmitate (Tween-40"). A second sample of the material was impregnated with an aqueous emulsion containing the above ingredients in onehalf the amounts stated above. In both cases the epoxy resin and polyamide resin were as described in Example I. The emulsions were applied in such manner that the material picked up about 100% of its weight of the emulsion. The impregnated samples were dried in an oven at 50 C. for 30 minutes than cured in an oven at 110 C. for one hour. I

The cured samples of knitted fabric and a sample of the untreated fabric (control) were subjected to washing followed by length measurements to determine the degree of shrinkage. The washing was conducted in a householdtype of washer having a power driven agitator. The washing solution at 38 C. contained 0.1% neutral soap and 0.002% of water softener (Calgon). The shrinkage of the samples was measured after 30 minutes and minutes of continuous washing. (In these tests the washer was manually controlled to stay in the washing cycle.)

The results obtained are tabulated below:

Shrinkage in length, percent Sample Treatment After After 30 min. 80 min. wash wash 5% epoxy resin and 5% polyamide resln- 0 O 2.5% epoxy resin and 2l5%-polyamideresm. 0 7. 5 None (control) 21. 2 43. 8

It was also observed that the control sample after the 80 minute wash had a boardy, felt-like texture and it was so denselytfelted that its knitted structure could hardly 'be detected with the naked eye. The treated samples (1 and 2) remained soft and flexible like the original material before treatment or washing.

EXAMPLE V A solution was prepared containing 10% total concentration of polyepoxide and polyamide dissolved in 80% ethanol. T he proportion of polyepoxide to polyamide was 10 parts by weight of the former to parts by weight of the latter. The polyepoxide was a commercial preparation (Epon 562) being the reaction product of epichlorhydrin and glycerol and containing on the average a little more than 2 epoxy groups per mol of glycerol. The compound can be considered as essentially a diglycidyl ether of glycerol. It is a liquid at ordinary temperatures, has a viscosity of 0.9 to 1.5 poises at 25 C. and has an epoxide equivalent of 140-165. The polyamide was a commercial product (Versamid 115) being a condensation product of diethylene triamine and heat-dimerized unsaturated fat acid. It was a viscous liquid at ordinary temperatures with a viscosity of Age-A1 on the Gardner- Holdt scale at 25 C. and a specific gravity of :99 at 25 C.

Pieces of wool cloth were padded with the alcoholic solution described above with a liquid pickup of about 100% by weight. The impregnated samples Were dried at 50 C. for 20 minutes then cured in an oven at 105 C. for 120 minutes.

Shrinkage tests were conducted on the treated wool cloth and on untreated samples of woolen cloth. The re sults are tabulated below-- Area shrinkage, percent Treated wool- 3.0 Untreated wool 34.0

EXAMPLE VI Samples of woolen cloth were padded with aqueous emulsions of polycpoxide' and polyamide in a total concentration of 4% but at various relative proportions of polyepoxide and polyamide, as set forth below. In two instances, cloth samples were padded with aqueous emulsions containing only polyepoxide or polyamide for comparative purposes. All the emulsions contained of iso-octyl phenyl ether of polyethylene glycol (Triton X- 100), based on the total weight of polyepoxide and polyamide, as an emulsifying agent. The polyepoxide and polyamide used in these tests were the same as described in Example V.

After impregnation with the aqueous emulsions, the cloth samples were dried and cured in an oven at 125 C. for 30 minutes.

A series of tests were conducted on the cured cloth samples, as follows Shrinkage was determined by measurements after washing as described in Example I.

Tensile strength and elongation were determined by the cut-strip method ASTM D-39-49.

Wrinkle recovery was measured with the Monsanto tester with a 1.5 lb. weight in accordance with ASTM test method D-1295-53T.

Tear strength was determined with the Elmendorf falling-pendulum tester in accordance with ASTM D-1424- 56T.

The results obtained are tabulated below- Total p ly- Weight epoxide ratio, and Area Tensile Elonga- Wrinkle Tear Sample polypolyshrmkstrength, tion at recovstrength amide amide age, lbs. break, ery,pergrams to polydepospercent percent cent epoxide ited on cloth, percent 100:0 9. 1 v 35. 7 27. 4 34. 6 87 1, 440 80:20 6. 3 19.0 27. 6 34. 9 96 1, 356 70:30 4. 6 2. 5 28.0 35. 3 88 1, 356 50:50 3. 6 2.0 27.2 36. 5 87 1, 356 30:70 3.5 g 2.0 26.9 33.8 87 1, 369 20:80 3. 2 6. 9 27. 2 33.2 87 1, 516 0:100 3. 7 22. 0 23. 6 25. 0 82 1, 837 None None 36. 0 25. 6 30. 7 84 1, 606

It was further observed that samples 1 to 6 immediately after curing were considerably stiffer than the untreated cloth (sample 8). However, after washing in conventional soap and water medium, the samples became soft 12 and virtually indistinguishable in hand from the untreated cloth sample. 7

EXAMPLE VII Woolen socks knitted from 2/ 28 wool yarn were impregnated with aqueous emulsions containing equal parts by weight of polyepoxide and polyamide. The total concentration of polyepoxide and polyamide in the emulsions were varied from about 5 to 10% to provide different uptakes of resin on the socks. The polyepoxide and polyamide were those described in Example V. After impregnation the socks were cured in an oven at 125 C. for 25-30 minutes.

In some instances the socks prior to impregnation were given a pre-treatment. This involved in one instance (A) soaking the socks for 1 hr. at 50 C. in a 0.8% aqueous solution of tetrasodium pyrophosphate. In another instance (B) the same pretreatment was used but hydrogen peroxide was added to the aqueous bath in a concentration of 2 volumes.

After curing, the sockswere subjected to repeated washings in a household-type Washer having a power driven agitator. The washing solution was at 60 C. and contained 0.1% neutral soap and 0.015% of water softener (Calgon). In each case a washing cycle of 60 minutes was used by manual control of the washer. Following each cycle of Washing and rinsing, the socks were given a 60-minute tumble dry at 6877 C.

After each 60-minute washing cycle, the foot length of socks (toe to heel) was measured to determine shrinkage. Sock length measurements were made while the socks were stretched under a 10-lb. load.

The results are tabulated below-- Total polv- Shrinkage Shrinkage Shrinkage Pretrcatepoxide and after after after Sample ment' polvamlde 1st wash, 3rd wash, 5th wash,

on socks, percent percent percent percent None 34. 5 t7. 7- 51. 4 5. 4 2. 63 1. 2 2. 3 7. 1 5. 59 5.0 i 5.0 None 2 11.1 21. 7 i 18.7 8.0 l. 5 0 1 +1. 9 9. 5 3. 8 1. 4 1.4 7. 7 1 +1. 4 3. l 4. 6 7'. 9 +2; 4' 1. 9 0. 7

=plus sign indicates that sock did not shrink but increased in length.

Norn.A=prctreatment in 0.8% aqueous tetrasodiurn pyrophosphate at 50 C. B=pretreatrnent in 0.8% aqueous tetrasodium pyrophosphate containing hydrogen peroxide in concentration 012 volumes.

EXAM PLE VIII Aqueous emulsions were prepared containing a total concentration of 10% of polyepoxide A, polyepoxide B, and polyamide. Five percent of iso-octyl phenyl ether of polyethylene glycol (Triton X-lOO), based ontotal weight of polyepoxides and polyamides, was used as the emulsifying agent. In these emulsions the proportions of polyepoxides and polyamides were varied as indicated below. Polyepoxide A was the same as described in Example V (essentially diglycidyl ether of glycerol). Polyepoxide B was a commercial product (Epon 828), essentially the diglycidyl ether of 2,2-bis (2,3-epoxypropoxyphenyl) propane. The polyamide was as described in Example V.

The emulsions described above were padded onto samples of woolen cloth with a wet pickup of about The cloth samples were then cured in an oven at C. for 30 minutes. The cured cloth samples were washed as described in Example I then measured to determine the area shrinkage. The washings were repeated a second time and shrinkage again measured. After the first Washing the cloth samples were tested to determine their flexural rigidity by the cantilever method ASTM D 1388- 5ST.

The formulations employed in Example VII are especially desirable from the standpoint of providing maximum shrink resistance coupled with minimum alteration of the natural hand of the textile. In adidtion, these formulations may be rapidly cured. Such a consideration is especially desirable for continuous operation. For example, where the dispersion applied to the textile contains the above-described agents in the proportion of 50% polyamide, 40% polyepoxide A, and polyepoxide B, the following curing times may be employed:

Curing temperature, "C: Time, min. 125 10-20 150 3-10 170 2-5 Having thus described our invention, we claim:

1. The process of dimensionally stabilizing a woolcontaining textile without impairing its hand which comprises impregnating a wool-containing textile with a polyepoxide containing at least two epoxy groups per molecule and a polyamide of a polyamiue and a polycarboxylic acid, the total amount of polyepoxide and polyamide deposited on the textile being about from 0.5 to 10% of the weight of the textile, said deposit being insuliicient to impair the hand of the textile but suflicient to give dimensional stabilization, and curing the impregnated textile by heating it at an elevated temperature to cure and insolubilize the deposit on the textile fibers.

2. The process of shrinkproo-ling wool without impairing its hand which comprises impregnating wool with an aqueous emulsion of a polyepoxide containing at least two epoxy groups per molecule and a polyamide of a polyamine and a polycarboxylic acid to deposit on the Wool about from 0.5 to 10% by weight of polyepoxide and polyamide, said deposit being insufiicient to impair the hand of the wool but sufiicient to give shrinkproofing, and curing the impregnated wool by heating it at a temperature about 14 from to 200 C. to cure and insolubilize the deposi on the textile fibers.

3. The process of claim 2 wherein the polyepoxide is a glycidyl polyether of 2,2-bis(parahydroxyphenyl)propane.

4. The process of claim 2 wherein the polyepoxide is a glycidyl polyether of glycerol.

5. The process of claim 2 wherein the polyamide is a polyamide of an aliphatic polyamine and a polymerized high molecular weight fatty acid.

6. The process of claim 2 wherein the polyamide is a polyamide of a lower aliphatic polyamine and a polymerized high molecular weight fatty acid.

7. Dimensionally stabilized wool-containing textile material of substantially unimpaired hand comprising fibrous wool-containing textile material, the fibers forming said material carrying an in situ heat-cured deposit of a polyepoxide containing at least two epoxy groups per molecule and a polyamide of a polyarnine and a polyearboxylic acid, in an amount about from 0.5 to 10% by weight on the textile insufiicient to substantially impair the hand of the textile but sufiicient to give dimensional stabilization.

8. Shrinkproofed wool of substantially unimpaired hand comprising wool, the fibers forming said wool carrying an in situ heat-cured deposit of a polyepoxide containing at least two epoxy groups per molecule and. a polyamide of a polyamine and a polycarboxylic acid, in an amount about from 0.5 to 10% by weight on the wool insufiicient to substantially impair the hand of the wool but sutlicient to give shrinkproofing.

9. The product of claim 7 wherein the polyepoxide is a glycidyl polyether of 2,2-bis(parahydroxyphenyl)propane.

10. The product of claim 7 wherein the polyepoxide is a glycidyl polyether of glycerol.

11. The product of claim 7 wherein the polyamide is a polyamide of an aliphatic polyarnine and a polymerized high molecular Weight fatty acid.

References Cited in the file of this patent UNITED STATES PATENTS 2,450,940 Cowan et al Oct. 12, 1948 2,589,245 Greenlee Mar. 18, 1952 2,689,193 Lipson et a1 Sept. 14, 1954 2,696,448 Hammer et a1 Dec. 7, 1954 2,730,427 Suen Ian. 10, 1956 2,752,269 Condo et al June 26, 1956 2,890,097 Coe June 9', 1959 2,933,409 Binkley Apr. 19, 1960 

1. THE PROCESS OF DIMENSIONALLY STABILIZING A WOOLCONTAINING TEXTILE WOTHOUT IMPAIRING ITS HAND WHICH COMPRISES IMPREGNATING A WOOL-CONTAINING TEXTILE WITH A POLYEPOXIDE CONTAINING AT LEAST TWO EPOXY GROUPS PER MOLECULE AND A POLYAMIDE OF A POLYAMINE AND POLYCARBOXYLIC ACID, THE TOTAL AMOUNT OF POLYEPOXIDE AND POLYAMIDE DEPOSITED ON THE TEXTILE BEING ABOUT FROM 0.5 TO 10% OF THE WEIGHT OF THE TEXTILE, SAID DEPOSIT BEING INSUFFICIENT TO IMPAIR THE HAND OF THE TEXTILE BYT SUFFICIENT TO GIVE DIMENSIONAL STABILIZATION, AND CURING THE IMPREGNATED TEXTILE BY HEATING IT AT AN ELEVATED TEMPERATURE TO CURE AND INSOLUBILIZED THE DEPOSIT ON THE TEXTILE FIBERS. 